Welcome to the forums.
I assume you mean tbbMeter, which has a dedicated forum
To answer the question, it only measures the usage of the machine it is installed on, and can only be installed on Windows systems. So it doesn't sound as though it will be much use to you.
If there are a number of Windows systems then the sum of their usages is available on the tbbMeter website if you register each installation.
You also need to make sure it only measures WAN traffic, not movements between kit on your LAN.
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